Early Results from SWIFT's BAT AGN Survey: XMM Follow-up Observations for 22 BAT AGNs Lisa Winter Lisa Winter (Grad Student at UMD) Richard Mushotzky (GSFC), Jack Tueller (GSFC), Craig Markwardt (GSFC), Christopher Reynolds (UMD)

SWIFT BAT Survey The Swift BAT is an 'all sky' instrument- covering ~20% of the sky at any one time and ~ 50% of the sky each day when not triggering on GRBs Sensitive in the keV band Random nature of GRBs leads to relatively uniform sky coverage for BAT- sensitivity 1-3 mC, angular accuracy ~1.7' Extensive follow-up of sources by the two other telescopes on SWIFT (UVOT and XRT) with relatively short exposures

‘Unbiased’ Survey All previous AGN surveys were biased (wrt obscuration) Much larger sample than HEAO-1 (and Integral)-1st sensitive all sky hard x-ray survey in 28 years ! BAT data provides first large unbiased sample of host galaxy properties Direct comparison with z~1 Chandra and XMM surveys * Distribution of N(H) values * Luminosity function * Log N-Log S *necessary for modeling x-ray background

SWIFT BAT Survey Compared to Other X-ray Surveys Brandt & Hasinger 05 Sy2 Sy1 I-mag calculated from 2MASS K-mag assuming K-I = 2 (Ferraras et al. 99 ) +1 0 Log(F X /F I ) -2

Follow-up Observations ks XMM observations from 26 proposed sources Sources selected:  Detected with BAT as a 5 sigma or higher detection  Optical counterpart clearly seen in DSS/2MASS images  No previous X-ray spectrum X-ray contours from SWIFT’s XRT

X-ray Properties of the Sources XMM follow-up sources: -Range of fluxes (F X ( keV)) from 1.6x to 3.0x erg/s cm 2 -8 “unabsorbed” sources (n H < ) -14 “absorbed” sources, 5 of which are “Compton thick” Log n H (cm -2 ) Compton thick BAT AGN XMM Follow-up Log F X ( keV)

Spectral Energy Distributions Simultaneous XMM OM data in U, UVW1, UVM2, and UVW2 filters In addition to the OM data, nearly all of the sources will have SWIFT UVOT data available. BAT keV 2-10 keV keV XMM OM Sy2 Sy1

Characteristic XMM X-ray Spectra Unabsorbed ESO 362-G018 Mkn 352 n H = cm -2 Fe K eqw = 450 eV NGC 1142 CGCG n H = cm -2 Compton thick Fe K eqw = 260 eV

Fe K-alpha lines and Compton thick sources Many of the Compton thick sources in the BAT sample have Fe EW <500 eV For example Mkn 417 has Fe EW ~70 eV and yet is clearly Compton thick It is not yet clear what this means BAT

BAT + XRT/XMM spectra We can check variability between XRT and XMM obs keV keV 12 of 20 sources with XRT and XMM spectra are variable by 20% or more ~ 100 days ESO 362-G018

Summary With XMM and XRT data, we are compiling SEDs for the BAT AGN sample With XRT and other (XMM, Chandra, etc.) X- ray observations we are collecting information on source X-ray variability. Interesting results:  11/14 absorbed sources show weak soft emission  Compton thick sources with small Fe K equivalent widths (as low as 70 eV for Mrk 417)

Future Work XMM Proposal for ~ 25 absorbed XRT sources/sources with no X-ray spectrum Working to obtain optical spectra for sources with none published/publicly available (roughly 15% of the current BAT AGNs have no optical spectra available) Analysis of the Swift XRT spectra